Perception最新文献

Investigating sensory processes in active human observers is critical for a holistic understanding of perception. Recent research shows that locomotion can rhythmically alter visual detection performance, illustrating how natural behaviours influence sensory processing. Here, we tested whether the speed and phase of locomotion also modulate temporal perception, focusing on the perceived synchrony of supra-threshold audio-visual stimuli. Participants made synchrony judgements over a range of stimulus onset asynchronies (SOAs) while walking at either slow or natural walking speeds. Slow walking decreased temporal sensitivity and increased reaction times compared to when walking at a natural pace. Further analysis of the shortest SOAs revealed that perceived synchrony was also biased by the relative phase of the step-cycle: with an increased bias to perceive synchrony during the swing phase, and decreased bias at the start and end of each step. Together, these results extend recent evidence that walking dynamically modulates near-threshold visual detection to include the modulation of supra-threshold audio-visual timing judgements.

Understanding speech in noisy environments is challenging, even for normal-hearing individuals, due to the complex interactions between auditory sensory processing and cognitive functions. The auditory system transforms acoustic signals into perceptual representations that are actively maintained and manipulated by working memory (WM). WM enables the retention and integration of incoming auditory information, supporting speech perception. While age-related speech perception decline is well documented in older adults, early signs of cognitive decline remain less explored in younger adults. This may be explained by the fact that conventional assessments conducted in quiet settings may not be sufficiently sensitive to detect such early signs of decline. The current study aims to explore early changes in WM abilities among adults aged 20-40 years by introducing background noise in the assessment task. Eighty normal-hearing participants were divided into four age-based groups (5-year intervals) and tested using forward digit span, backward digit span, and operation span tasks. Additionally, SNR-50 (signal-to-noise ratio at which 50% of the stimuli are correctly identified) was measured to assess speech perception in noise. Results showed a gradual age-related decline in WM performance, with significant reductions in backward and operation span performance appearing in the 35-40 age group, especially under noisy conditions. Moreover, significant negative correlations were observed between SNR-50 and WM across both quiet and noisy conditions. The findings suggest that WM decline may begin earlier than traditionally assumed in challenging auditory environments. This highlights the importance of assessing auditory cognition under ecologically valid conditions and supports cognitive load theory by demonstrating how noise increases cognitive demand, impairing performance.

This study examines the perceptual expertise basis of the own-age bias (OAB)-better recognition of faces from one's own age group-in young (n = 64; 19-30 years) and older adults (n = 64; 69-80 years). Participants engaged in an old/new recognition task involving upright and inverted young and older faces. The results revealed a robust OAB in the younger group, characterized by a reduced face inversion effect ("FIE")-more accurate recognition for upright versus inverted faces-when processing older/other-age faces compared to the pronounced FIE for own/younger-age faces. This difference was primarily driven by disrupted performance for upright older faces vs. upright young faces. In contrast, no OAB was observed in the older group, which exhibited a strong FIE for both own/older- and other/younger-age faces, with upright older faces being recognized more accurately than in the younger group. These findings underscore the importance of perceptual expertise in explaining the OAB.

In order to achieve color constancy, the visual system needs to estimate the illuminant by referring to the chromatic distribution information in scenes where direct cues to the illuminant were absent. In this study, color constancy was investigated by an achromatic setting with short illuminant durations in five kinds of scenes with different numbers of colors and colored patches. Three of these scenes contained 8, 24, and 96 patches with different colors, and two other scenes contained 96 patches with 8 and 24 colors, respectively. All five scenes had identical space-averaged means, but different variances. The results showed that the color constancy index decreased as the variance of scene colors increased. This indicates that the effect of the number of colors and patches on color constancy was dependent on the scene variance they produced: a greater number of colors and patches tended to generate higher variance, which in turn led to lower color constancy indices. The results suggest that color constancy under brief exposure to multicolor scenes cannot be fully explained by models based on adaptation to the illuminant or mean chromaticity of the scene. Instead, the distribution of colors around the mean also plays an essential role.

Understanding everyday events is essential for navigating and facilitating successful social interactions. Face recognition is thought to play a critical role in how we associate and interpret events in the real world. In this study, we explored this issue using a natural viewing paradigm in which participants watched a movie containing a rich and detailed narrative. To determine the importance of face recognition in event comprehension, we compared age-matched, neurotypical control participants and individuals with developmental prosopagnosia (DP) - a lifelong deficit in the ability to recognize faces. After watching the movie, participants were assessed on their comprehension of the events from the movie. We found that DPs showed a significant reduction in their understanding of the events from the movie compared to neurotypical controls. We also found that individual differences in face recognition predicted event comprehension. Together, these results demonstrate the importance of face recognition for understanding naturally unfolding events in everyday life.

The Ebbinghaus illusion is a size illusion, in which a central circle appears larger or smaller depending on the size of surrounding circles. This illusion is widely used to study group-level differences in attentional processing, with the proposal that a local-processing bias reduces susceptibility to the Ebbinghaus illusion. One hundred and forty-five participants (87 young; 58 older) were included in the analyses. Participants completed the Navon hierarchical-figures task, to measure the global-local processing bias, and the Ebbinghaus illusion task, to measure susceptibility to the illusion. First, we investigated whether a strong local-processing bias reduced susceptibility to the Ebbinghaus illusion. Our findings did not support this proposal. At the group level, older participants demonstrated worse performance for global processing compared to young participants, but there were no age-group differences in susceptibility to the illusion. At the individual level, the young and older participants with the stronger local-processing bias were the participants with greater susceptibility to the illusion. Second, we investigated whether longer inspection times during the Ebbinghaus illusion task reduced susceptibility to the illusion. Our findings did support this proposal. At the group level, there were no age-group differences in either inspection time or susceptibility to the Ebbinghaus illusion. At the individual level, we replicated previous findings-the participants with the longer inspection times were the participants with the least susceptibility to the illusion. We discuss alternative cognitive mechanisms that may account for the Ebbinghaus illusion and their relevance to age-related changes and individual differences in visual attention.